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authorCyril Bur <cyrilbur@gmail.com>2016-02-29 17:53:50 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2016-03-02 23:34:49 +1100
commit6f515d842e8e1b205e54f44b9013bf14870b97a7 (patch)
tree34f133da5b1cd6922f2728645db025bcc81b4183 /arch/powerpc/kernel/process.c
parent8792468da5e12e77e76e1edf081acf0392abb331 (diff)
downloadop-kernel-dev-6f515d842e8e1b205e54f44b9013bf14870b97a7.zip
op-kernel-dev-6f515d842e8e1b205e54f44b9013bf14870b97a7.tar.gz
powerpc: Add the ability to save Altivec without giving it up
This patch adds the ability to be able to save the VEC registers to the thread struct without giving up (disabling the facility) next time the process returns to userspace. This patch builds on a previous optimisation for the FPU registers in the thread copy path to avoid a possibly pointless reload of VEC state. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/process.c')
-rw-r--r--arch/powerpc/kernel/process.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index a7e5061..14c09d2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -213,6 +213,16 @@ static int restore_fp(struct task_struct *tsk) { return 0; }
#ifdef CONFIG_ALTIVEC
#define loadvec(thr) ((thr).load_vec)
+static void __giveup_altivec(struct task_struct *tsk)
+{
+ save_altivec(tsk);
+ tsk->thread.regs->msr &= ~MSR_VEC;
+#ifdef CONFIG_VSX
+ if (cpu_has_feature(CPU_FTR_VSX))
+ tsk->thread.regs->msr &= ~MSR_VSX;
+#endif
+}
+
void giveup_altivec(struct task_struct *tsk)
{
check_if_tm_restore_required(tsk);
@@ -472,7 +482,7 @@ void save_all(struct task_struct *tsk)
save_fpu(tsk);
if (usermsr & MSR_VEC)
- __giveup_altivec(tsk);
+ save_altivec(tsk);
if (usermsr & MSR_VSX)
__giveup_vsx(tsk);
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